Also, it seems like the older Testors clear enamel gets, the more it yellows. I pulled an older build off the shelf a few days ago and was kinda surprised at how much it had yellowed. I had sprayed it over Boyd's Pacific Blue and even over that color, the yellowing was still noticeable. I also made the mistake of spraying it over white that now looks more like Wimbledon White.
So far, I've had no yellowing at all with Tamiya TS-13. The oldest build I have with it over white is around three years old. But, it is still as clear as the day I shot it on so far.
I don't like using Future as a clear coat on bodies. I tried it three times and gave up on it. Only one attempt looked decent. But for some reason,it has spider web cracks that appear and disappear

on the hood,top and trunk. I surely wouldn't trust it over white. The bottle I have has yellowed slightly inside the bottle.